Field of the Invention
The present invention relates to a two component resin and, more particularly, to a pumpable two component resin system and method for the installation of mine roof bolts.
Description of Related Art
The roof of a mine is conventionally supported by tensioning the roof with steel bolts inserted into boreholes drilled in the mine roof that reinforce the unsupported rock formation above the mine roof. The mine roof bolt may be anchored mechanically to the rock formation by engagement of an expansion assembly on the distal end of the mine roof bolt with the rock formation. Alternatively, the mine roof bolt may be adhesively bonded to the rock formation with a resin bonding material inserted into the borehole. A combination of mechanical anchoring and resin bonding may also be employed by using both an expansion assembly and resin bonding material.
When resin bonding material is utilized, the bonding material penetrates the surrounding rock formation to adhesively join the rock strata and to firmly hold the roof bolt within the borehole. Resin is typically inserted into the mine roof borehole in the form of a two component plastic cartridge having one component containing a curable resin composition and another component containing a curing agent (catalyst). The two component resin cartridge is inserted into the blind end of the borehole and the mine roof bolt is inserted into the borehole such that the end of the mine roof bolt ruptures the two component resin cartridge. Upon rotation of the mine roof bolt about its longitudinal axis, the compartments within the resin cartridge are shredded and the components are mixed. The resin mixture fills the annular area between the borehole wall and the shaft of the mine roof bolt. The mixed resin cures and binds the mine roof bolt to the surrounding rock. The mine roof bolt is typically rotated via a drive head.